Comparison of Two Solutions of Quadrature Oscillators With Linear Control of Frequency of Oscillation Employing Modern Commercially Available Devices

Abstract

This paper proposes two circuits of frequency-controlled oscillators, whose structures are based only on simple commercially available active elements with minimum number of terminals, in particular, the differential voltage buffer, controllable B Roman Sotner Circuits Syst Signal Process voltage amplifier and electronically controllable current conveyor. Two methods for achieving linear control (tuning) of frequency of oscillations (FO) are discussed. The first method employs a simple structure. However, the generated signal level (amplitude) depends on the tuning process. This is a drawback of this method. The second method solves this drawback completely, and the generated signals have constant amplitudes during the tuning of FO. The expected behavior is confirmed by laboratory experiments utilizing commercially available high-speed active elements (current-and voltage-mode multipliers, video difference amplifier). Operational range was tested from frequencies of hundreds of kHz up to frequencies of tens of MHz.

Mixed-Mode Third-Order Quadrature Oscillator Based on Single MCCFTA

“…This problem can be solved by using automatic gain control (AGC) circuit. There are oscillators with AGC available in literature [58][59][60][61]. These techniques use AGC circuit including into the loop of the system for controlling the amplitude of signal.…”

“…14 was used. This circuit was adopted from [61]. From our pretest on the proposed circuit, it was found that V 1 (I 1 and I 3 ) was dependent on tuning of FO, thus V 1 will be used for the input of AGC circuit (V in(AGC) ).…”

“…Although, higher FO for experimental results was possible, but our test was investigated the circuit which builds on perfboard. Using printed circuit board and high quality active devices the operation band of the circuit [59][60][61] will be increased. Therefore, this experimental result was used only to confirm the workability of the proposed structure.…”

Pseudo-Differential Filter Design Using Novel Adjustable Floating Inductance Simulator with Electronically Controllable Current Conveyors

“…Proposed floating inductance simulator shown in Fig. 1 employs three electronically adjustable current conveyors of second generation (ECCIIs) [16] described by the following inter-terminal transfers: IZ = B.IX, VX = VY, IY = 0 and one differential voltage buffer (DVB) [16] providing the following operation: V+  V = Vout. Note that the current gain B of each ECCII is controllable linearly by DC voltage (B  VSET_B).…”

Current/Voltage Controlled Quadrature Sinusoidal Oscillators for Phase Sensitive Detection Using Commercially Available IC

“…The synthesis of an analog circuit using commercially available ICs have been continuously proposed [16][17][18][19][20]. Especially the designs of voltage or current controlled quadrature sinusoidal oscillators using commercially available ICs have been found in the open literature [21][22][23][24][25][26][27][28][29][30][31]. Moreover, the linear voltage controlled sinusoidal oscillator using commercially available ICs-based CCII was proposed in [32].…”